The invention relates to a novel display system, and to in particular illuminated display boards.
Originally, illuminated display boards were essentially display boards with an external light source. For example, a billboard with lights. Smaller displays were generally even less sophisticated and were not even illuminated.
As the market grew and the need for advertising increased so has the need for more sophisticated but just as simple display systems.
With the advent of translucent plastics, back-illuminated signs and displays have become very popular. This type of system essentially comprises a bank of lights, generally the fluorescent variety with a translucent sheet with the sign applied thereto; either by the way of painting or etching and the like. Large banks of lights are often required to illuminate the entire surface of the signs. A disadvantage of such back-illuminated signs is that a large number of lights are required, increasing running costs and maintenance costs since they are continually needing to be replaced. Furthermore, when one light needs to be replaced generally the entire sign needs to be dismantled, which is a great inconvenience when a large sign is involved.
Clear sheet materials with the sign directly applied to the surface have recently been used. However, the problem with these types of signs/displays, as with the back-illuminated signs, a number of lights are required to fully illuminate the sign. In this case the display requires a light source along each edge of the sheet in order for the sign to be illuminated and even then the middle portion of the display is not illuminated to the same degree as the edges.
The prior art has attempted to increase the degree of illumination of translucent and transparent mediums and generally these attempts have not been particularly successful when applied to larger areas which is often the case with signs. Illumination of a small area is generally easier and an attempt at increasing the illumination of a small area is discussed in U.S. Pat. No. 3,241,256. This patent dealt with providing uniform brightness on instrument dials, scales and indicator tapes, generally small in nature. A dot pattern was applied to the rear side of the light transmitting block only wherein the block is supported by a plate. As with previous systems, when larger areas are required to be illuminated, a number of light sources are required to fully illuminate the entire area of the sign.